Purpose:
Studies suggest binocular video game therapies may effectively treat amblyopia in older children and adults, who are outside the critical window for traditional patching. Dichoptic video game training involves complementary game elements shown to both eyes, with the amblyopic eye seeing a higher contrast image. We are evaluating the safety and efficacy of a new immersive virtual reality (VR) system as a dichoptic amblyopia therapy. An additional study aim is to validate at home VR-based therapy and to compare visual parameters with in-office clinical examinations.

Methods:
We are conducting a single-center, masked, placebo-controlled study of the effect of 3-dimensional, VR gameplay on visual acuity (VA) and stereopsis in subjects with amblyopia. Approximately 50 participants between the ages of 15 and 45 with moderate vision loss from anisometropic and/or strabismic amblyopia are being enrolled. Subjects are randomized into three arms, comparing at-home dichoptic gameplay to monocular patching or binocular non-dichoptic gameplay. After an initial three-week period of patching or gameplay at home, all subjects receive the dichoptic intervention for an additional three weeks. Office-based testing is supplemented with novel in-game at-home diagnostic testing and compliance monitoring. Durability of treatment will be evaluated six months after enrollment. Primary study outcomes are VA in the amblyopic eye and stereopsis. Secondary outcomes include quality of life (AS-20 questionnaire), binocular Sloan low contrast acuity, and safety.

Results:
Pilot data supports a beneficial effect in amblyopic patients, with reduced suppression after 3 hours of gameplay. More than 300 users have trialed this system without reporting persistent diplopia or other bothersome side effects. In control subjects with varied levels of vision, measures of acuity and stereopsis from clinical examinations correlate with in-game testing metrics.

Conclusions:
Dichoptic VR treatment may be safe and effective in reducing suppression in young adults with amblyopia. Our randomized-controlled study will formally test the effects of dichoptic VR therapy on VA and stereopsis. Home-based VR systems also enable remote diagnostics and monitoring and should encourage compliance. Our initial results also support a role for remote testing in rigorous studies of candidate vision therapies.